Electronics > Beginners

Purchasing parts and basic components for a new lab

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ez24:
I suggest do not get 1/4 w resistors, the leads are too thin especially using cheap boards.  Somewhere on this forum there are suggestions on how to pick a good cheap board vs a bad cheap board.   You have to use a mag glass and examine the "fingers".  Maybe someone with a better memory will let us know.  I agree with others, a cheap board will drive you nuts.

AnyNameWillDo:
Are there any good kits with 74HC/74HTC logic chips? I'm only finding the same kit everywhere and it only has one of each:

https://www.ebay.com/itm/30-Types-74HC-Series-Logic-IC-Assortment-Kit-High-Speed-Si-Gate-CMOS-IC-In-As/202107524516

Maybe I am better off sourcing things individually from Digikey for these...

tooki:

--- Quote from: AnyNameWillDo on July 24, 2018, 10:11:52 pm ---I did look at those 3M boards on the AS site, but there so many variants and types that I got overwhelmed without knowing more and lost track of it. Unless I missed a comment somewhere, is the SS252 what you were referencing? Edit: However the shipping charges on the AS site are steep -- price is lower to get the 3M board on ebay in this case.
--- End quote ---
I wasn’t referring to any specific model. I personally find it handy to have various size breadboards, from little tiny things like the TS273, all the way to big ones like BB318. Sometimes it’s nice to have the baseplate, sometimes it’s nice to have a little bare breadboard. Just depends on the project, you know?

Yes, AS’s shipping is steep, but their prices are so low on the actual items that it’s worth it. (For example, a single 3M ACE309 is $44 on Digi-Key, vs $16 (!!) on AS for the BB309. Even with shipping it’s cheaper, but if you make a sensible order of, say, 5 or 6 various size breadboards, you’ll come out ahead even compared to eBay.

I’ve only got one 3M breadboard at the moment. I keep meaning to place an order with AS to pick up when I’m in the US next... I’m tired of using the cheap ones where components easily pull out... I also found (and threw out) some among my cheap ones with such bad contacts that there were several ohms (!) contact resistance. In analog especially, stuff like that can ruin your day. But loose contacts suck regardless of what type of circuit it is.


--- Quote from: AnyNameWillDo on July 24, 2018, 10:11:52 pm ---I'll check out those other components too -- thanks

741: Unsure of this one as of yet... lots of variants.

NE552 I think: https://www.ebay.com/itm/10-x-NE5532-5532-Dual-Low-Noise-Op-Amp-IC-Texas-Brand-USA-SELLER-Free-Shipping/223015694297

TL072: https://www.ebay.com/itm/10-x-TL072-LOW-NOISE-J-FET-DUAL-OP-AMP-IC-USA-Seller-Free-Shipping/323271252084

CD4017 decade counter: https://www.ebay.com/itm/10-x-CD4017-4017-DECADE-COUNTER-DIVIDER-IC-TEXAS-BRAND-USA-SELLER-Free-Shipping/323161690070
--- End quote ---
NE5532: FYI, should you get into audio stuff, then eventually you might consider ordering some guaranteed-genuine NE5532’s from Digi-Key. They perform better than the who-knows-where-they-came-from ones off eBay. But for experimenting, the eBay ones are fine.

If you’re considering a digi-key order anyway, you might just get these jellybean ICs from them. They’re in the same price ballpark as this Thaishine vendor at quantities of 10 (but fromm digikey you can also just order just 2 or 3 to play with), and you’ll know they’re genuine.
UA741: https://www.digikey.com/product-detail/en/texas-instruments/UA741CP/296-11107-5-ND/382197
TL072: https://www.digikey.com/product-detail/en/texas-instruments/TL072IP/296-14997-5-ND/563039
NE5532: https://www.digikey.com/product-detail/en/texas-instruments/SA5532AP/296-16995-5-ND/656520 (The SA prefix is the extended-temperature version, the -AP means guaranteed low noise. For whatever reason these are cheaper than the regular version!)
CD4017: https://www.digikey.com/product-detail/en/texas-instruments/CD4017BE/296-2037-5-ND/67253
555: https://www.digikey.com/product-detail/en/texas-instruments/SE555P/296-9684-5-ND/380221 (again, extended-temp version is cheaper here)



--- Quote from: AnyNameWillDo on July 24, 2018, 10:11:52 pm ---555 timers: https://www.ebay.com/itm/50PCS-NE555P-NE555-NE555N-DIP-8-SINGLE-BIPOLAR-TIMERS-IC-US-SHIPPING-M175/113156855492

--- End quote ---
I don’t think you need to get 50 pieces. ;) Get a few and see from there if they’re something you want to use a lot or not. Some people find a way to put a 555 in seemigly every project, others quickly dismiss them altogether and rely on small microcontrollers. Play around and see which camp you end up gravitating towards. :)


--- Quote from: AnyNameWillDo on July 25, 2018, 01:48:14 am ---Are there any good kits with 74HC/74HTC logic chips? I'm only finding the same kit everywhere and it only has one of each:

https://www.ebay.com/itm/30-Types-74HC-Series-Logic-IC-Assortment-Kit-High-Speed-Si-Gate-CMOS-IC-In-As/202107524516

Maybe I am better off sourcing things individually from Digikey for these...

--- End quote ---
I wouldn’t buy any in advance. Assuming discrete logic is even something you want to get into (cuz an Arduino can do most of this stuff cheaper and easier, so it’s purely a mental exercise) you can use digital logic simulator software to actually design and debug the logic, and then you’ll know what gates you need and can start making a parts list.


I forget if someone mentioned them yet, but one other thing I’d get a few of is MOSFETs (logic-level, ideally), since they let you control bigger loads (like LED strips) from the small signals from an Arduino.
For example: https://www.digikey.com/product-detail/en/vishay-siliconix/IRLZ14PBF/IRLZ14PBF-ND/811728 (10A, very fast)
https://www.digikey.com/product-detail/en/infineon-technologies/IRLB8748PBF/IRLB8748PBF-ND/2127672 (78A, a bit slower)

Again, maybe just get a few to play with and then later order as needed for projects. (Tip: though it won’t include all brands, searching for MOSFETs that begin with “IRL” is an easy way to restrict to logic-level ones. [“IR” originally stood for the vendor “international rectifier”.])

Here’s a fun exercise, one straight from some projects of mine: rig up an LED strip to be PWM dimmed from an Arduino via a MOSFET. Try different MOSFET types with different specs and use your oscilloscope to see how different ones turn on and off at different speeds. (The gate capacitance of a MOSFET affects its speed and its resistance when turned on: small capacitance is fast but gives higher resistance, larger capacitance is slower but gives lower resistance. Think about, and visualize with the scope, how this affects efficiency at a given PWM rate, given that a MOSFET’s resistance is worst during the transitional period between fully-on and fully-off, so that’s when it’s going to be inefficient and give off heat.)

AnyNameWillDo:
Yeah, as of yesterday, finally starting to understand the DigiKey site a little better -- getting the ICs/chips there instead.

AnyNameWillDo:
What about clips, leads, wires to actually connect components on boards, etc?

e.g. stuff like
https://www.amazon.com/gp/product/B0002KRABU/
https://www.amazon.com/gp/product/B0002JJU1Y/
https://www.amazon.com/gp/product/B0002JJU3C/

or something else/more?

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